铸铁生产中,为了获得珠光体灰口铸铁,可以采用的方法有()。
A.孕育处理;
B.适当降低碳、硅含量;
C.提高冷却速度;
D.A、B和C;
E.A和C。
参考答案:D
Mrs. Taylor has______ 8-year-old daughter who has_____ gift for painting
--- she has won two national prizes.
A.a; a
B.an; the
C.an; a
D.the; a
脱落脉见于
A.心房颤动
B.Ⅱ度房室传导阻滞
C.频发性早搏
D.窦性心律不齐
E.完全性房室传导阻滞